Soluble oil containing ether derivatives of polyhydroxy alcohols



soap into a practically true solution in oil- Patented Dec. 17, 1929 UNITED STATES PATENT 'orrics DAVID B. HERB-H LL, 0]! LONG- BEACH, CALIFORNIA, ASSIGNOB '10 UNION OIL COM- rm OF CALIFORNIA, OF LOS ANGELES, CALIFORNIA, A. CORPORATION OF CALI- ZI'OBNIA SOLUBLE OIL CONTAINING ETKER DERIVATIVES OF EOLYHYDBOXY ALCOHOLS Io Drawing.

This invention relates to the production of the so-called soluble oils which disperse readily when added to water for the preparatifin of sprays, dips, cutting oils and the li e.

In producing these soluble oils, a neutral oil, which commonly is of mineral origin, and a soap are employed in conjunction with a common solvent or blending a ent; Sodium naphthenate or other soap 0 the same type may be employed as the soap required, and while the present invention is not limited to the use of a naphthenate it is especially adapted thereto.

The chief object of the invention is to employ a common solvent or blending agent which shall possess better blending power for the soap and oil than has been known heretofore, and one which shall at the same time have a more pleasant and less pronounced odor than often obtained in. the past. This agent, in a preferred form, should be particularly suitable for employment with an alkali metal naphthenate such as sodium naphthenate, and since such an agent is also suitable where other alkali metal soaps are used it may therefore be employed with either the naphthenates or said other soaps.

In working upon soluble oils, I have found that the common solvent for the soap and oil should be of such character as to bring the in the cold, as distinguished from a colloidal solution or jelly. For soaps of the sodium naphthenate type, the common solvent employed should be' partly soluble in water but not miscible therewith in all proportions, due to the fact that a solvent which is miscible :with water in all proportions will largely leave the oil and dissolve in water when the soluble oil is poured into water,-thus leaving the soap and oil in a form which will not readily disperse in the water. In other words the blending agent employed must be soluble in the oil and must also have solubility in water, and a more or less careful balance must be maintained in these solvent properties. This balance ,I have found to be advantageously effected by the inclusion of an ether group in the molecule of a poly- Application iled January 4, ms. Serial no. 244,562.

droxy-alcohol, whereby there is present in the solventa hydroxyl group to lend solubllity in water and an other group to promote solubility in oil at the same time. compound of this character has high solvent power for the soaps. Such hydroxy-ethers may be of several types, for instance, monoether derivatives of the glycols or diether derlvatives of glycerol; or, otherwise stated, any ether derivative of a polyhydroxyalcohol whichderivative contains at least one free hydroxyl and which possesses the required solubility. This applies particularly to the lower polyalcohols, and opens up the field to those hydroxy-ethers of the lower alcohols which are soluble to some extent in both oil and water.

Thus, the invention in a broad aspect resides in the preparation of a soluble oil from a neutral oil (animal, vegetable or'mineral) and sodium naphthenate or other soap, by means of a blending agent in the form of a hydroxy-ether which is a common solvent for both the oil and soap and possesses limited solubility in water. More particularly the common solvent is one which will act to bring the soap into a substantially true solution in the oil. In a preferred form this common solvent or blending agent is an ether derivative of a polyhydroxy-alcohol which derivative contains a free hydroxyl and possesses the solvent properties stated. For the most part this places the alcohol base in the class of the polyhydroxy-alcohols having a maximum of four hydroxyl groups, it being important only that the proper solubility be maintained.

Considering the invention in greater detail, the soluble oil is produced by treating soap and a neutral oil with a common solvent which acts as a blending agent. The

cold, as shown v blending agent. As indicated above the best results are obtained, especially with soa s of the sodium naphthenate type, when t e common solvent is somewhat soluble 1n water but notmiscible in all proportions. The reason for this is to revent the solvent from leaving the solub e oil and dissolving in water when the oil is poured into water and thus leaving the soap and oil beh ndso that ready dispersion is impossible, as will happen when one employs a solvent-which is miscible in all proportions in water, such as ethyl-alcohol.

Thus, to insure proper solubility in the oil'and also in Water, especially where the naphthenates are employed, a careful balance must be established. This can be accomplished by using an a ent which contains an hydroxyl group an an ether group, the hydroxyl group lending water solubility and the ether group lending oil solubility, such a compound not being wholly soluble in Water and at the same time offerin high solubility for the soap employed. Suc substances are hydroxy-ethers, and all those hydroxy-ethers which possess the requisite solvent properties above outlined are suit able agents. This class-is defined as those derived from polyhydroxy-alcohols having not more than four hydroxyl groups. Al-

cohols having a greater number of hydroxyls have molecu r weights that are too high to yield the desired solvent properties. Thus,

hydroxy-ethers which have such desired propity and a hy erties are ether derivatives of the lower polyhydroxy-alcohols particularly the dihydroxyalcohols (glycols) and the trihydroxy-alcohols such as glycerol. Specific examples'in .these groups are monoethyl-ether of ethylene glycol and dipropyl-ether of glycerol. Other monoethers of ethylene glycol may be used as well as monoethers of other glycols. Likewise, similar derivatives of glycerol besides dip'ropyl-ether may be used as well as others of the trihydroxy-alcohols, as long as a free hydroxyl group remains. Some other radical than the ether group may be introduced in place of one of the ether groups in glycerol, thus retainin an ether group or oil solubildroxyl group for water solubilitv. A diether formed by substituting two ether groups for two of the four hydroxyls of erythritol may be used, and so on so long as the series does not become so .high that the desired solubility smaller. Thus the is lost, or the ether groups are not so overbalanced in number by hydroxyl groups that the water solubility becomes excessive as com 'ared with the oil solubility and effectively function of the ether groups. Monoethers of the glycols present a particularly satisfactory group which includes the mono-methyl, ethyl, propyl and butyl ethers of ethylene glycol or of propylene glycol. I

All'of these solvents possess the desired properties above mentioned of blending or bringing into solution a relatively large quantity of soap with theoil by employing only a relatively small quantity of the blending solvent, and the solution so produced is a true solution of the soap in the oil as established by the low viscosity of the mixture. The resulting soluble oil emulsifies freely and disperses readily upon dilution with water in all proportions. v

As a specific example, a sodium naphthenate was used which had been prepared by neutralizing naphthenic acid with sodium hydroxide solution (for example 40? B.) and heating the soap thus formed to drive off most of the water, the water content being reduced to somewhat less than 8%. To 25 parts of this soap there was added parts of neutral mineral oil-and 5 parts of monoethyl-ether of ethylene glycol, the ether I being introduced at a temperature of about 120 F. to avoid excessive evaporation. The product was a homogeneous oily material of low viscosity which emulsified readily in water with little or no agitation and in all proportions.

Results such as this are always obtained unless too much water has been left in the soap, 8% or less of water being a sufii'ciently small amount. The presence of excessive water is indicated by lack of homogeneity of the soluble oil mixture.

Various oils may be used in preparation of the product desired, for example, light oils such as'kerosene, or heavy oils such as crude oil or heavy lubricating oil, the resulting products emulsifying readily in Water and the emulsions remaining stable under all degrees of dilutions. Corresponding results may be obtained with vegetable oils such as cotton seed oil, or animal oils such as fish oils, or mixtures of these with each other or with mineral oil, although emulsions formed from oils of purely mineral origin are -in general the most stable.

Soluble oils prepared according to the foregoing pass all government tests including the corrosion and odor tests, and since the common solventsdescribed are unusually effective as blending agents for the soap and oil the required amount of such solvents is somewhat v blending features and the improved odor present very desirable advantages.

It is to be understood that the above discloestroys the desiredv soap and ,4; part of a blend-Lugl sures are not to be considered as limiting but merely as illustrative of the generic invention, Los

and that many variations may be made within the scope of the claims.

I claim:

1. A s'dluble oil comprising an oil containin in solution a soap and a hydroxy-ether sofuble iii both the oil and water.

2. A soluble oil according to claim 1 wherein the soap is a naphthenate.

3. A soluble oil comprising an oil, a soap and a blending agent in the form of an ether derivative of a polyhydroxy-alcohol which derivative retains a free h droxyl and which derivative is soluble in bot the oil and water.

4. An oil according to claim 3 wherein the soap is a naphthenate.

5. A soluble oil according to claim 3 wherein the oil 'employed is a mineral oil.

6. A soluble oil comprising a neutral oil, a naphthenate sea and a common solvent in the fornilof a hy roxy-ether which is at least partly so uble in the oil but only partl miscible with .Water. o

7. A soluble oil comprising an oil, a soap and a common solvent capable of bringing the soap into a practically true solution in the oil, saidsolvent being a hydroxy-ether of a polyhydroxy-alcohol and having solubility being partly soluble in water.

8. A soluble oil comprising an oil, a soap and a blending agent in the form of a hydr oxy-ether derived from a polyhydroxy-alco 01 which origi: ally contained from two to four hydroxyls.

9. A soluble oil airising a mineral oil, a

Si ed at Wilmington, in the county of geles and State of California, this 19th day of December, A. D. 1927.

DAVID R. MERRILL.

naphthmte p and monoethyl-ether of I ethylene glycol.

10. A soluble oil comprising an oil, a soap and a blending agent in form of a monoether of a g1 col.

11. soluble oil com rising a solution of approximately 5 parts 0 neutral oil, 1 part of a soap and part of a blending agent containing an ether group to impart solubility in the oil and a free hydroxyl to impart solubility in water.

12. Asoluble oil comprising a proximately 5 pnrtsiof mineral oil, 1 part 0 naphthenate a ent which is an ether derivative of a poly ydroxy-alcohol, thederivative containing a free hydroxyl group and having both oil and water soluility.

5 13. soluble oil according to claim 1 wherein the soap is soluble in water.

14. soluble oil according to. claim 1 wherein the soap is an alkali metal naphthanate.

15. A soluble oil comprising a neutral oil, a water soluble soap, and a monoether of a glycol serving as a blending agent and soluble in both oil and water.

I 16. Soluble oil according to claini 15 wherec; in the soap is an alkali metal naphthenfite. 

